Question

18 g glucose is added to 178.2 g of water the vapour pressure of water for this aqueous solution at ${100}^{0}C$ is:

• A. 704 torr
• B. 759 torr
• C. 7.6 torr
• D. None of these

Answer 1

The correct option is D None of these

Molar mass of water $=18$ $g$

For $178.2$ $g$ of $H_2$ ,$n_A=9.9$ $X_B=\frac{0.1}{0.1+9.9}=0.01$

Molar mass of Glucuse $=180$ $g$ $X_A=0.99$

For $18$ $g$ , $n_B=0.1$

For lowering of vapour pressure ,

$P=P^o\times A=P^{o}A(1-X_B)=760(1-0.01)$

$P=760-7.6$

$P=752.4$ $torr$